But how can the Emperor guard against rebellion by one of these governors? Or revolt by a local planet’s population? The answer is simple: He can zip around in the baddest weapon in the galaxy, destroying his foes with the push of a button. No foe could fight back, and the DS is mobile enough to respond to multiple threats in short order.
Note that this scheme provides an easy answer to the question, “how can we afford a Death Star?” If the scheme works, the Death Star will pay for itself dozens of times in the additional tax revenue from fearful planets, and by the money not spent by the military putting down revolts with conventional weapons.
But will it work? Only if it induces cooperation through fear. Every planet blown up represents a tremendous loss of potential future revenue, so like nuclear weapons today, the actual use of the DS is a calamity. Moreover, like nuclear weapons, they only work as a deterrent if they are used judiciously. Citizens throughout the galaxy must believe that failure to pay their taxes and comply with their Imperial masters will lead to detonation, but also that compliance will save them. The fact that the DS was used against Alderaan, however, would likely have had the opposite effect. Alderaan is “peaceful” and “has no weapons.” It was detonated because its teenage senator was secretly aiding the Rebel Alliance and waited too long to give up Dantoonie. To me, that’s a little too Caligula to induce rational compliance. One imagines the conversations on other planets: